T-SQL (SS2K8) :: Database Triggers To Prevent Large DDL Transactions?
Mar 2, 2014
A server I'm working on has a very unique situation, where user tables and production tables reside on the same database. Users update / create tables or populates these tables, so it can't be a table-specific trigger. However, they give a new meaning to "kamikaze pilots" as it's not uncommon for them to "accidentally" update / insert / delete 500,000,000 + records in a single statement. I've tried educating them to use batching, but to no avail, so now I'm forced to stop these statements BEFORE they execute, based on rowcount, as they fill up the database log so quickly that it goes into recovery mode (It has a 200GB log file - insane, I know).
I recon the mosts transactions allowed should be 1,000,000 records in a single statement. Looking for database trigger to stop them from executing statements with large records?
I have triggers in place on a table that do various checks on data input. It is clear that because of these triggers I cannot do updates on multiple records in this table. When I do, I receive an error that "subquery returned more than one value." Is there anyway to work around this by temporarily turning off triggers or something else?
I found out that executing the procedure SP_INDEXOPTION and setting 'AllowRowLocks' to false i can prevent the sql server from locking rows in a table and 'AllowPageLocks' prevents from pages being locked. I need to preform same operation in case of tables. I need to perform insertion operations concurrently and acquire required locks manually. Is there a way to stop sqlserver from acquiring locks on the table. I need to disable all the locks (row, page and table).
I'm trying convert my working CLR Trigger to a Linq-based implementation, but I don't seem to be able to get Linq to cooperate with the Trigger's context transaction (a local SubordinateTransaction with IsolationLevel="ReadCommitted").
For brevity's sake I've boiled down my scenario to a bare minimum: A SQL table [Test] with three columns (int Manual, int Automatic, IDENTITY int ID) needs any external updates on its [Manual] column to be applied to its [Automatic] column (with an additional sign change) through a Trigger.
A fairly direct translation of my non-Linq CLR Trigger to Linq yields the following code (the [Trigger_TestLinQs] SQL table has been modified to point to the Trigger's "INSERTED" table, [TestLinQs] points to the actual SQL table):
Code Snippet[SqlTrigger(Name = "LinQTrigger", Target = "dbo.TestLinQ", Event = "FOR INSERT, UPDATE")] public static void LinQTrigger() { SqlTriggerContext triggerContext = SqlContext.TriggerContext; if (triggerContext.TriggerAction == TriggerAction.Insert || triggerContext.TriggerAction == TriggerAction.Update) { //using (TransactionScope scope = new TransactionScope(Transaction.Current)) { /* err 6549 */ using (SqlConnection connection = new SqlConnection("context connection=true")) { connection.Open(); using (MyDataContext context = new MyDataContext(connection)) { List<int[]> updates = new List<int[]>();
foreach (Trigger_TestLinQ test in (from t in context.Trigger_TestLinQs select t)) { /* err 6522 */ if (test.Manual != null && triggerContext.IsUpdatedColumn(0)) updates.Add(new int[] { test.ID, -test.Manual.Value }); }
foreach (int[] update in updates) { dbo.TestLinQ test = (from t in context.TestLinQs where t.ID == update[0] select t).Single<dbo.TestLinQ>(); test.Automatic = update[1]; }
context.SubmitChanges(); } } // scope.Complete(); //} } } Running this on SQL Server 2005 / .NET 3.5 beta2 produces an Error 6522 "Cannot enlist in the transaction because a local transaction is in progress on the connection." in the line executing the Linq query because the Linq DataContext apparently insists on opening a transaction. The recommended pattern for DataContext query operations - running them inside a TransactionScope as indicated by the commented-out sections - unfortunately leads to a different Error 6549 in the TransactionScope constructor complaining about a missing MSDTC. And there shouldn't be a need for a distributed transaction here, should there? Using different TransactionScope constructors (TransactionScopeOptions.Required, TransactionOptions(){IsolationLevel=ReadCommitted}) did not make any difference, either.
What am I doing wrong here? Is there any way for the Linq DataContext to attach to the CLR Trigger's ambient transaction?
I am trying to run a query that deletes duplicates records on a table with 24m records. The problem is each time I run it the log file fills up and I get an error saying the log file is full. For this reason the query never ends.
Is there anyway to turn of logging when running a query?
I think it also has to do with disk drive runng out of space as the log file is growing to over 12gb.
I use the VB.NET transaction to update an sql server 2000 database. I call a number of stored procedures within this transaction.The stored procedures will update tables. These tables use triggers..My question is, when does the trigger get called? Is it after the each stored procedure, or is it after the whole transaction? Jag
I have to modify the table structure where the table have a lot of data already. The log is getting full due to uncommitted transactions, there is a lot of data being updated in large bulks, not all of the transactions are committed, the update task cannot be completed. However, there is no more spare disk space for it to commit the transaction. Anyone can help?
When I need to perform an update against multi-million row table Itypically specify @@rowcount, to reduce locks.e.g.set @@rowcount 1000while exists (select * from myTable where col2 is null)update myTableset col2 = col1 + 'blahblah'where col2 is nullHowever, my boss' script does something like this. I think it works OKbut it seems overly complicated to me. Any thoughts?while exists (....)begin traninsert into #tableselect ...update myTableset ...from myTable join #table ...(@numberOfRows is a counter variable, tracking #rows that have beenupdated since last batch)if @numberOfRows > 1000begincommitbegin tranendend
I have a table which when certain columns are updated, need a trigger to fire to update a next schedule date in that same table for that record. I can write the trigger, but my question for performance and efficiency is which approach would be better. Separate triggers fo the 8 columns, or a large trigger with an If to check if these columns are updated. Thanks
Hi there, I have decided to move all my transaction handling from asp.net to stored procedures in a SQL Server 2000 database. I know the database is capable of rolling back the transactions just like myTransaction.Rollback() in asp.net. But what about exceptions? In asp.net, I am used to doing the following: <code>Try 'execute commands myTransaction.Commit()Catch ex As Exception Response.Write(ex.Message) myTransaction.Rollback()End Try</code>Will the database inform me of any exceptions (and their messages)? Do I need to put anything explicit in my stored procedure other than rollback transaction? Any help is greatly appreciated
I am running the following query, which deletes around 800 million rows from the table.
I would like to introduce transactions with in this code and also, if success entire deletion process should be committed and number of rows deleted, table name and success should be inserted to the log table.
If there is a failure, transaction should be rolled back and table name and error message should be inserted to the same log file
Select 1 While @@ROWCOUNT > 0 Begin DELETE Top(100000) FROM [dbo].[Table1] FROM [dbo].[Table2] INNER JOIN [dbo].[Table3] ON [Table2].[PracticeID] = [Table3].[PracticeID] INNER JOIN [dbo].[Table1] ON [Table3].[InputDevicePracticeID] = [Table1].[InputDevicePracticeID] WHERE [Table2].PracticeID =55; End
Create table code ( id identity(1,1) code parentcode internalreference)
There are other columns but I have omitted them for clarity.
The clustered index is on the ID.
There are indexes on the code, parentcode and internalreference columns.
The problem is the table stores a parentcode with an internalreference and around 2000 codes which are children of the parentcode. I realise the table is very badly designed, but the company love orms!!
The table currently holds around 300 millions rows.
The application does the following two queries to find the first internalreference of a code and the last internal refernce of a code:
--Find first internalrefernce SELECT TOP 1 ID, InternalReference FROM code WHERE ParentCode = 'M222' Order By InternalReference
-- Find last ineternalreference SELECT TOP 1 ID, InternalReference FROM code WHERE ParentCode = 'M222' Order By InternalReference DESC
These queries are running for a very long time, only because of the sort. If I run the query without the sort, then they return the results instantly, but obviously this doesn't find the first and last internalreference for a parentCode.
I realize the best way to fix this is to redesign the table, but I cannot do that at this time.
Is there a better way to do this so that two queries which individually run very slowly, can be combined into one that is more efficient?
I work in Healthcare IS for Company A, but Company B is hosting one of our EMR programs for us. This was done on purpose, so that whether a patient is seen at one or the other, their medical history is more complete. However, this puts all of the data that I need to get to on a server across town that I can only access via Sql Server Management Studio as a linked server.
Now, in some ways, the performance has been better than I expected, but sometimes it behaves very erratically. I am using OPENQUERY to handle all of the pulls, and am not joining to any local tables, in order to maximize efficiency.
Here is some of the code I run, and what happens:
SELECT * FROM OPENQUERY([linkedservername], ' SELECT * FROM Encounter_ItemChild
[Code] ....
***The above query was programmatically generated by taking the IDs from the second query, and packing as many into the IN condition as possible. Each statement could hold only about 900 IDs, so around 70 queries get built...however, each one returns the records in question in 1-2 seconds.
My main question is...if the second query pulls all IDs from Encounter in a few seconds, and that query is used in the first query's WHERE clause, why does it spin and spin, while manually throwing the IDs in instead runs almost instantly?
I have a master table containing details of over 800000 surveys made up of approximately 400 distinct document names and versions. Each document can have as few as 10 questions but as many as 150. Each question represents one row.
My challenge is to create a separate spreadsheet for each of the 400 distinct document names and versions containing all the rows and columns present in the master table. The largest number of rows would be around 150 and therefore each spreadsheet will not be very big.
e.g. in my sample data below, i will need to create individual Excel files named as follows . . . "Document1Version1.xlsx" containing all the column names and 6 rows for the 6 questions relating to Document 1 version 1 "Document1Version2.xlsx" containing all the column names and 8 rows for the 8 questions relating to Document 1 version 2 "Document2Version1.xlsx" containing all the column names and 4 rows for the 4 questions relating to Document 2 version 1
I assume that one of the first things is to create a lookup of the distinct document names and versions assign some variables and then use this lookup to loop through and sequentially filter the master table data ready for creating the individual Excel files.
--CREATE TEMP TABLE FOR EXAMPLE
IF OBJECT_ID('tempdb..#excelTest') IS NOT NULL DROP TABLE #excelTest CREATE TABLE #excelTest ( [rowID] [nvarchar](10) NULL, [docName] [nvarchar](50) NULL,
Are there ways in SQL server to deny connecting to a instance? Basically i am looking for a way where data is accessed only through application , even the DBA's shouldn't have access to the data though they are sysadmins? Someone told me this is possible in SQL 2014? This is only for individual access, i know i can put some encryption in app layer.
how to prevent the insertion of the same entry of an unique value into the database? assume that I have a primary key username " abc" in the database and then I insert the "abc" again ,the debuggging error msg pops out saying the primary key cannot be duplicated.. how can I do an if--else statement to check the database against this unintentional inputs of the same unique data " abc"???
We utilise SQL scripts, executed via sqlcmd.exe, to upgrade the schema and common data of our database(s) when we deploy new versions of our software to a production site. At the moment we simply wait until after hours to do the upgrade and ask nicely for all users to not use the system for a while.
Obviously, asking nicely doesn't always work, and there is also the issue of scheduled server tasks and web services / web sites that operate against the database 24/7.
What are our options for putting the entire server (or preferrably just one database) into a semi-offline state so that users and services cannot connect to it while our script connects and performs the upgrade? I imagine there may be several approaches each with their own pros and cons.
If you could point me in the right direction or perhaps mention what strategy has worked for you, it would be greatly appreciated. We perform these upgrades from hundreds of kilometers away via VPNs and Remote Desktop so we can't just unplug the network cable :).
Does anyone have a good strategy or technique for preventing database drops in SQL Server 2000? I know in 2005 DDL triggers rock, but in 2000 what can you do to audit who drops a database why keeping the same permissions intact.
What I want is a trigger that is specific to my DB called "JunkStuff". I only want to block a servername from connect to my super dooper DB "JunkStuff".
vendor did a full backup for his database and put some folder not being backed up by TSM, he is the owner of the database, and delete his backup later. The backup is not copy only, all the differential and log backups taken are based on his FULL backup. so they cannot be restored.
QUESTION: To prevent this happen in the future, what is the normal practices? or any way to prevent db_owner to do the ad-hoc full backup? I am thinking of using DENY backup database, or write a policy claiming no responsibility if vendor make it happen again.
I have an application in dotnet that uses sql express. This application will be deployed on the user computer and I have to find a way to prevent the user to be able to read the data and access the structure of the database.
Is there a way to do this ? Even if the user is a local administrator of the computer ?
I'm working on inserting data into a table in a database. The table has two separate triggers, one for insert and one for update (I don't like it this way, but that's how it's been for years). When there is a normal insert, done via a program, it looks like the triggers work fine. When I run an insert manually via a script, the first insert trigger will run, but the update trigger will fail. I narrowed down the issue to a root cause.
This root issue is due to both triggers using the same temporary table name. When the second trigger runs, there's an error stating that a few columns don't exist. I went to my test server and test db and changed the update trigger so that the temporary table is different than the insert trigger temporary table, the triggers work fine. The weird thing is that if the temporary table already exists, when the second trigger tries to create the temporary table, I would expect it to fail and say that it already exists.I'm probably just going to update the trigger tonight and change the temporary table name.
I represent a software development house and we have developed a client server system based on SQL Server. Most of our customers have already purchased Enterprise License of SQL Server, therefore they own the SA Login and Password. We are bound to attach our Database with their Server on their machine.
My question is how can we stop a System Administrator of SQL Server to view our Database Structure, Queries, Data installed on their SQL Server on their machine.
Our database structure is a trade secret and we cant reveal the structure to the client.
please answer this question by email to me at farhandotcom@gmail.com
I tried to use dbo.tables of Northwind database in SQL Server Express to do SqlCommand to populate a DataTable in DataSet. The SqlCommand failed in the project execution and I found that Northwind database in SQL Server Express is busted and gone (just the name "Northwind" remained in the SQL Server Management Studio Express). How can I prevent it from happening in my "SqlCommand-SqlConnection" project? Please help and advise.
I tried to repair my "Northwind" database by using the SQL2000SampleDb.msi of Northwind and pubs Sample Databases for SQL Server 2000 downloaded from the http://www.microsoft.com/downloads. My "pubs" database is still in my SQL Server Management Studio Express. How can I just repair my "Northwind" database by using the Microsoft SQL2000SampleDb.msi program? Please help and advise this matter too.
Hi All, I would like to know write all transcations in the log file to the database with out doing full backup of the database.. Please let me know is there any dbcc statement or some other method to do this..
guys,I have a project need to move more than 100,000 records from onedatabase table to another database table every week. Currently, usersinput date range from web UI, my store procedure will take those dateranges to INSERT records to a table in another database, then deletethe records, but it will take really long time to finish this action(up to 1 or 2 hours).My question is if there is some other way I should do to speed up theaction, I am thinking about use bcp to copy those records to datafileand then use bcp to insert it into SQL Server table. Is this the rightway to do it or should I consider other solution (then, what is thesolution.)Thanks a lot!
This should be a fairly simple question. It's based on this error message:"Transaction count after EXECUTE indicates that a COMMIT or ROLLBACK TRANSACTION statement is missing. Previous count = 1, current count = 0." I get this when executing a stored procedure upon processing a form. This error happens when I intentionally provide input to the stored procedure that I know should cause it to error out. I catch the exception, and it contains the error message, but it also contains the above message added on to it, which I don't want. I won't post the entire stored procedure. But I'll list a digest of it (Just those lines that are significant). Assume that what's included is what happens when I provide bad input:BEGINBEGIN TRYBEGIN TRANSACTION RAISERROR('The item selected does not exist in the database.', 16, 1); COMMIT -- This won't execute when the RAISERROR breaks out to the CATCH block END TRY BEGIN CATCHROLLBACKDECLARE @ErrorSeverity INT, @ErrorMessage NVARCHAR(4000)SET @ErrorSeverity = ERROR_SEVERITY()SET @ErrorMessage = ERROR_MESSAGE() RAISERROR(@ErrorMessage, @ErrorSeverity, 1) END CATCH END Okay, so that works fine. The problem is when I execute this with an SqlCommand object, on which I've opened a transaction. I won't include the entire setup of the data (with the parameters, since those seem fine), but I'll give my code that opens the connection and executes the query: con.Open(); SqlTransaction transaction = con.BeginTransaction(); command.Transaction = transaction; try { command.ExecuteNonQuery(); transaction.Commit(); } catch (Exception ex) { transaction.Rollback(); } finally { con.Close(); } I'm calling the stored procedure listed above (which has its own transaction), using a SqlCommand object on which I've opened a transaction. When there is no error it works fine. But when I give the stored procedure bad data, it gives me that message about the transaction count. Is there something I need to do in either my SQL or my C# to handle this? The entire message found in the Exception's Message is a concatenation of the message in my RAISERROR, along with the transaction count message I quoted at the beginning. Thanks, -Dan
